Method for improving the adhesion of brass-coated steel cord to rubber

Abstract

Brass-coated steel cord is provided with improved adhesive characteristics for use in tire making, by coating it with certain combinations of sulfur-containing accelerators and phosphate corrosion inhibitors.

We claim: 
     
       1. Method of treating brass-coated steel tire cord to enhance its adhesion to rubber comprising forming a coating thereon of phosphate corrosion inhibitor and a sulfur-containing rubber vulcanization accelerator in a ratio of from about 0.8:1 to about 4:1. 
     
     
       2. Method of claim 1 in which the ratio of phosphate corrosion inhibitor to rubber vulcanization accelerator is from about 2:1 to about 3.5:1. 
     
     
       3. Method of claim 1 wherein the coating is formed by passing brass-coated wire through a slurry of phosphate corrosion inhibitor and accelerator, and forming the wire into a cord. 
     
     
       4. Method of claim 1 wherein the coating is formed by passing cord through a solution of phosphate corrosion inhibitor and accelerator in chloroform. 
     
     
       5. Method of claim 1 wherein the coating is formed by passing cord through a solution of phosphate corrosion inhibitor and accelerator in benzene or trichloroethylene. 
     
     
       6. Method of claim 1 in which the accelerator is a sulfur-containing thiazyl, thiuram, or dithiocarbamate. 
     
     
       7. Method of claim 1 in which the phosphate corrosion inhibitor is tricresylphosphate. 
     
     
       8. Brass-coated tire cord having on its surface a film of phosphate corrosion inhibitor and a sulfur-containing rubber accelerator. 
     
     
       9. Tire cord of claim 8 in which the phosphate corrosion inhibitor is tricresylphosphate. 
     
     
       10. Tire cord of claim 8 in which the sulfur-containing rubber accelerator is selected from the group consisting of ##STR5## where R 1  and R 2  are independently selected from lower alkyl groups, R 3  is selected from H and ##STR6## R 4  is selected from ##STR7## and M is selected from Zn, Cu, Bi, Pb, Se, and Te, X is 0 or 1 and Y is X or X-1.